tbuckley/cabot-search huggingface dataset:
Abstract P3106: Trametinib Decreases Electron Transport Chain Activity In The Uninjured Mouse Heart
Authors: Peyton B Sandroni
Journal: Circulation Research (2022)

Trametinib (Trm) is a highly selective inhibitor of the tyrosine kinases MEK1/2 used to treat patients with melanoma and non-small cell lung cancer featuring BRAF mutations. Although Trm is generally well tolerated, it is associated with adverse cardiovascular effects including heart failure. Furthermore, the mechanisms underlying this cardiotoxicity are unclear. Here, we assessed the hypothesis that Trm decreases oxidative phosphorylation in the mouse heart. Female FVB mice were treated with Trm (3 mg/kg/d) or vehicle (DMSO) via oral gavage (n = 10, each group). We assessed cardiac contractility on Day 0 and Day 7 using echocardiography. We then performed electron transport chain (ETC) enzyme assays in isolated cardiac mitochondria and RNA sequencing of cardiac tissue to assess ETC Complex I-IV enzyme activity and ETC transcript abundance, respectively. Additionally, we measured citrate synthase (CS) activity as a marker for mitochondrial abundance. Mice treated with Trm had decreased fractional shortening on Day 7 compared to Day 0 (Panel A, 47.7 ± 1.6% vs. 55.5 ± 0.8%, p &lt; 0.001) (mean ± SEM), confirming the cardiotoxicity of our treatment model. Additionally, mice treated with Trm had increased lung weight to heart weight (LW/HW) ratios compared to vehicle controls (Panel B, 1.69 ± 0.11 vs. 1.39 ± 0.03, p = 0.01), indicating heart failure. Mice treated with Trm had decreased CS (7,235 ± 586 vs. 8,562 ± 192 nmol/mg/min, p = 0.024), Complex II (1,659 ± 207 vs. 2,239 ± 239, p = 0.04), and Complex IV (3,979 ± 460 vs. 5,576 ± 615, p = 0.03) activities with a trend towards decreased Complex III (2,703 ± 452 vs. 3,554 ± 434, p = 0.09) activity (Panel C). Mice treated with Trm had decreased transcript abundance of Complex I (41 of 43), Complex II (6 of 6), Complex III (8 of 8), and Complex IV (18 of 23) transcripts (Panel D). Gene Ontology cellular compartment analysis of transcriptomic data revealed that Trm treatment primarily alters abundance of transcripts related to the mitochondrion (Panel E, p adj = 3.2 x 10 -113 ). KEGG Pathway analysis revealed that oxidative phosphorylation was the most significantly altered process following Trm treatment (Panel F, p adj = 2.9 x 10 -27 ). Collectively, these findings suggest that Trm causes widespread decreases in ETC activity that may hinder cardiomyocyte oxidative phosphorylation and contractility.
Abstract P2104: Adeno-associated Virus Serotype 5 Is A Suitable Vector For S100a1-based Gene Therapy Of Post-ischemic Chronic Cardiac Dysfunction
Authors: Dorothea Kehr, Janek Salatzki, Birgit Krautz, Erhe Gao, Karl Varadi, Jennifer Birkenstock, Philipp Schlegel, Oliver Müller, Philip W Raake, Michael Egger, Walter J Koch, Johannes Riffel, Florian André, Hugo A Katus, Norbert Frey, Andreas Jungmann, Martin Busch, Helga Pfannkuche, Patrick Most
Journal: Circulation Research (2022)

Introduction: For S100A1-based heart failure gene therapies, AAV9 and 6 have shown efficacy in pre-clinical large animal studies. As AAV9 has shown concerning signs of toxicity in clinical studies and AAV6 displays poor production yields, there is need for a novel safe and cardiac-specific AAV serotype. Hypothesis: We hypothesized that in a pig model the safety proven and scalably manufacturable AAV5 may be a suitable vector for S100A1-based gene therapy of post-ischemic cardiac dysfunction. Methods: AAV production, 2h balloon-occlusion of the LCX, retrograde cardiac gene delivery, cardiac MRI, late gadolinium enhancement (LGE), global T1 relaxation, qPCR, RNA-Seq, WGCNA, KEGG, Reactome, LAD-ligation mouse model Results: In a comparative study of AAV5-, 6- and 9-luciferase (luc) in healthy farm pigs (n=5 each; 1x10 13 vgc/pig), AAV5 achieved a more homogeneous cardiac apical-basal transduction pattern than AAV6 with a higher luc activity than AAV9. In a clinically relevant endpoint driven study, we demonstrated a significant improvement in EF (+19 ± 5 %) 12 weeks after retrograde AAV5- S100A1 gene delivery compared to AAV5-luc in infarcted pigs (n=4 each; 1x10 13 vgc/pig). Moreover, S100A1 -treated pigs showed significantly less infarct extension (-0.5 ± 0.3 g vs. 5 ± 1.3 g (luc)) measured by cardiac MRI. There were no unfavorable alterations in blood chemistry or ECG. S100A1 expression was predominantly contained to the heart. The WGCNA unveiled a significant correlation between the improved EF and a suppression of inflammatory and immunological pathways (r=-0.96, p &lt; 0.01) and between the absent infarct extension and enhanced activity of cardioprotective signaling (r=-0.82, p &lt; 0.05). With injections of 2х10 11 vgc of AAV5- S100A1 or AAV5-gfp (n=4 each) into the remote myocardium in the mouse model, we confirmed a significant improvement in FS (+43.8 ± 8.8 %, vs. gfp) and suppression of inflammatory gene expression including i.e., IL1b or TNFa by S100A1. Conclusion: We conclude that AAV5 is suitable for S100A1-based gene therapy of post-ischemic cardiac dysfunction and that this vector/target combination can help accelerating the way towards a clinical trial. We also found novel signaling pathways that may be involved in S100A1’s therapeutic actions.
Abstract P3046: Deletion Of Sarm1 Nad Hydrolase Ameliorates Diabetic Cardiomyopathy
Authors: Hina Lateef Nizami, Christine Light, Haiwei Gu, Chi Fung Lee
Journal: Circulation Research (2022)

Diabetes is a risk factor for heart disease. NAD depletion has emerged as a hallmark of cardiometabolic diseases, and hence, elevating NAD level alleviates diabetic cardiomyopathy. On the other hand, inhibition of NAD consumption also maintains NAD homeostasis. SARM1 is a novel intracellular NAD hydrolase that contributes to diabetic neuropathy; however, its role in heart disease has never been described. We assayed 243 plasma metabolites from wild-type (WT) and SARM1-KO (KO) mice by quantitative metabolomics, and found that SARM1 deficiency caused changes in more (67) metabolites in male mice than in female mice (28). Only 5 of these metabolites overlapped between male and female, indicating sex-dependent effect of SARM1 deletion on plasma metabolites. SARM1 deficiency may alter susceptibility of male mice to metabolic stress, since metabolites associated with diabetes and impaired metabolism were altered, e.g. pyridoxic acid, alloisoleucine, LPC/PC, ceramide etc. Despite the differences in plasma metabolite levels, KO mice from either sex did not show changes in cardiac structure and function at baseline. We next tested a hypothesis that SARM1 deficiency protects mice against diabetic cardiomyopathy. WT and KO mice were challenged with streptozotocin (STZ) to induce diabetic stress. 16-week diabetes promoted progressive systolic (fractional shortening) and diastolic dysfunction (E’/A’, e/E’) in WT male mice. SARM1 deficiency attenuated diabetes-induced cardiac dysfunction, although fasting glucose levels were similarly elevated in diabetic WT and KO mice. Diabetic WT hearts showed declined NAD level, which was elevated by SARM1 deficiency. The restored NAD level in KO hearts did not change expression of other NAD hydrolases (Bst1 and CD38). Diabetic WT hearts up-regulated cardiomyopathy markers such as nppb and Nox4 mRNAs, and myh7/myh6 ratio, that were normalized by SARM1 deficiency. Chronic diabetes promoted cardiac fibrosis and upregulation of profibrotic gene expression such as ctgf and Inhbb, that were suppressed by SARM1 deficiency. Our data suggest a protective effect of SARM1 deficiency on diabetic cardiomyopathy in male mice. The effects of SARM1 deficiency on diabetic hearts could be sex-dependent and remain to be determined.
Abstract P3115: The Protective Effect Of Canagliflozin Against Carfilzomib-induced Endothelial Toxicity
Authors: Mohamed S Dabour, Ibrahim Abdelgawad, Marianne Grant, Beshay Zordoky
Journal: Circulation Research (2022)

Introduction: The anti-cancer agent carfilzomib (CFZ) is associated with serious cardiovascular side effects. There is anecdotal clinical evidence that endothelial dysfunction contributes to CFZ-induced cardiovascular complications; however, the toxic effects of CFZ have not been reported in endothelial cells (ECs). The anti-diabetic Sodium glucose cotransporter 2 (SGLT 2 ) inhibitors have newly emerged as cardio-protective agents in heart failure, myocardial infarction, stroke, and diabetic cardiomyopathy. The objectives of the current work are to characterize the toxic effects of CFZ in two human-derived endothelial cell lines, human umbilical vein endothelial cells (HUVECs) and EA.hy926, determine the molecular signaling changes associated with these toxic effects, and investigate the protective effects of SGLT 2 inhibitors (Empagliflozin, Dapagliflozin, Canagliflozin) on CFZ-induced endothelial toxicity. Methods: Both ECs were treated with clinically relevant concentrations of CFZ (0.05, 0.1, 0.2, 0.5, and 1 μM) for 24 hours. EA.hy926 cells were treated with 0.5 μM CFZ with or without SGLT 2 inhibitor (0.1, 1, 10, 50, 100 μM). Cell viability was determined by the MTT assay and protein expressions of apoptotic markers, mitogen-activated protein kinases (MAPKs), and the p70S6K pathway were determined by western blotting. Results: CFZ reduces cell viability and induces apoptotic cell death in the two cell lines in a concentration-dependent manner. CFZ-induced apoptosis is also associated with activation of the p38 and JNK MAPK pathways and a remarkable inhibition of the p70S6K pathway. In EA.hy926, Canagliflozin prevents reduction in cell viability caused by CFZ, while empagliflozin and dapagliflozin have not shown any protective effects in vitro. Mechanistically, canagliflozin abrogates CFZ-induced endothelial cell apoptosis, and prevents CFZ-induced JNK activation. Conclusion: This is the first study to report the endothelial toxicity of CFZ. CFZ induces endothelial cell apoptosis which may contribute to CFZ-induced cardiovascular complications and canagliflozin protects against CFZ endothelial toxicity. Future research is warranted to identify the protective effects of SGLT 2 inhibitors against CFZ in vivo.
Abstract P3037: Metabolic Transitions In The Developing Mouse Heart
Authors: Gisela Beutner, Jonathan Burris, Michael P Collins, Denise Fangnibo Hanvi, Ethan D Cohen, Michael O'Reilly, Paul S Brookes, Karen Bentley, George A Porter
Journal: Circulation Research (2022)

During cardiac development, cellular energy production evolves dramatically. Mechanisms that control these changes and activation of electron transport chain (ETC) remain unclear. Our aim was to provide a comprehensive analysis of mitochondrial biology and bioenergetics in the developing wild type heart for use in experimental models, such as mice, in which the mitochondrial protein, cyclophilin D (CyPD), was deleted. Mouse hearts were harvested from wild type and CyPD null hearts throughout development and examined by electron microscopy, liquid chromatography/mass spectrometry, oxygen consumption and enzyme assays, gel electrophoresis/immunoblotting, and calcium retention capacity (CRC). As the heart develops, myocyte size and mitochondrial number, size, and complexity increases with transitions at the end of the embryonic period and immediately after birth. Metabolomic profiling demonstrated changes in glycolysis, the TCA cycle, and redox state during development and these changes may facilitate proliferation in the neonatal heart. Activation of ETC complexes I, III, IV, and V occurs in the mid-embryonic period, while assembly of ETC supercomplexes begins at the late embryonic period. In contrast, complex II activity is relatively stable during development. CRC assays demonstrated a gradual decrease in the probability of mPTP opening during development, and while CyPD expression increased, its specific enzymatic activity decreased. For most assays tested, these metabolic transitions occurred earlier in development in CyPD null mice. In conclusion, the developing heart undergoes changes in cellular bioenergetics with two transitions at the end of the embryonic period and immediately after birth. Deletion of CyPD causes these transitions to occur earlier in development, suggesting that CyPD and closure of the mPTP controls mitochondrial activation and bioenergetics during cardiac development.
Abstract P3061: A Monoclonal Antibody Blocking Interleukin-1 Receptor Accessory Protein Reduces Acute Viral Myocarditis Severity
Authors: Diego A Lema, Monica Talor, Sara Rattik, Caitriona Gronberg, David Liberg, Daniela Cihakova
Journal: Circulation Research (2022)

IL-1, IL-33 and IL-36 have complementary, pro-inflammatory roles during the immune response that promote autoimmune diseases, particularly myocarditis. While antibodies that neutralize circulating cytokines exist, we hypothesized that blockade of their shared co-receptor, IL-1 receptor accessory protein (IL1RAP), would exhibit a more potent and broader anti-inflammatory profile. The CAN10 antibody blocks IL1RAP and is currently under development for treating severe autoimmune and inflammatory diseases. To investigate if IL1RAP blockade is an effective treatment of cardiac inflammation, we induced autoimmune viral myocarditis in 8-week-old Balb/c male mice with Coxsackievirus B3 and treated them with mCAN10, an anti-mouse IL1RAP monoclonal antibody. Mice were euthanized at day 10, the peak of acute inflammation in the heart. IL1RAP blockade reduced the severity of myocarditis at this timepoint when compared to isotype, saline or IL-1 receptor antagonist (IL1RA) treatment (the gold standard in IL-1 receptor blockade), without affecting viral clearance from the heart. Spectral flow cytometry of heart immune populations revealed that mCAN10 significantly reduced the number of infiltrating leukocytes of broad populations, especially effector CD4 + and CD8 + T cells, inflammatory Ly6C + CCR2 + monocytes, neutrophils and eosinophils. We also observed early echocardiographical parameters suggesting improved heart function, including ejection fraction, fractional shortening and interventricular septum diameter. Interestingly, mCAN10-treated mice demonstrated reduced proliferation of bone marrow precursors of inflammatory myeloid and lymphoid lineage leukocytes. Splenic immune cell populations were not affected, indicating that mCAN10 does not cause global immune suppression in these animals. Altogether, our data show that a single monoclonal antibody targeting three inflammatory cytokine systems, IL-1, IL-33 and IL-36, potently reduces acute viral myocarditis severity in a broader fashion that is not recapitulated by IL-1α/β blockade, and shows translational promise for therapeutics of inflammatory disease. Phase I clinical studies of the CAN10 antibody are in preparation.
Biochemistry and turnover of lung interstitium
Authors: JM Davidson
Journal: European Respiratory Journal (1990)

The lung contains a host of extracellular matrix components that comprise the supporting and adhesive elements of conducting airways, alveoli and the vascular tree. While none of these components is unique to the lung, their peculiar distribution determines the architecture and function of this gas exchange organ. Cells and tissues of the lung interact with the matrix through a variety of surface receptors, especially the integrins and adhesive molecules, some of which may play important roles in lung injury and repair. Collagen type I is the predominant determinant of tensile strength, but as many as 11 other genetic types of collagen with specialized adhesive and connecting functions can be found in various lung structures, including cartilage and basement membranes. Excessive matrix accumulation in the lung is the result of a complex set of influences on gene regulation, part of which may be due to the presence of inflammatory cytokines that directly stimulate matrix synthesis. However, degradation and turnover of the matrix are also critical processes influenced by many of the same mediators. Collagenase and gelatinase (type IV collagenase) are tightly-regulated metalloenzymes that, together with a set of specific inhibitors of metalloproteinases, determine the net abundance and distribution of collagen. Elastases of several biochemical types are also under tight regulation by proteinase inhibitors. Elastin is essential to lung function at the level of alveolar wall resiliency and patency, and loss of elastin in emphysema appears to be due to uncontrolled degradation of the embryologically-established pattern of elastic fibres accompanied by nonfunctional replacement as a response to injury. Injury to the vascular endothelium of the lung, as well as other physiological insults that elevate pulmonary blood pressure, can lead to the excessive accumulation of collagen and elastin in the conductance and resistance arteries of the pulmonary circulation. Mechanical stress and endothelial injury may mediate the medial hypertrophy of these vessels. Extracellular matrix components are critically involved in every stage of lung biology: development, normal function and acute and chronic disease states. To date, only glucocorticoids, cross-linking inhibitors, and protease inhibitors have been used in a general attempt to suppress either excessive matrix accumulation or loss. More detailed understanding of the regulation and specific interactions of matrix components is central to the analysis of disease states and the development of appropriate therapeutic strategies.
Abstract P3009: Fatty Acid-binding Proteins Promote Pulmonary Arterial Hypertension Via Upregulation Of Endothelial Glycolysis
Authors: BIN LIU, Dan Yi, Jiakai Pan, Karina Ramirez, Michael Fallon, Zhiyu Dai
Journal: Circulation Research (2022)

Introduction: Pulmonary arterial hypertension (PAH) is a disaster disease characterized by obliterative vascular remodeling and persistent increase of vascular resistance, leading to right heart failure and premature death. Understanding the cellular and molecular mechanisms will help develop novel therapeutic approaches for PAH patients. Hypothesis: We hypothesize that endothelial fatty acid metabolism is critical for obstructive vascular remodeling in the pathogenesis of PAH. Methods: A severe mouse model of PH Egln1 Tie2Cre mice were bred with Fabp45 -/- mice to generate Egln1 Tie2Cre / Fabp45 -/- mice. We applied single-cell RNA sequencing (scRNA-seq) to profile the pulmonary cells in Egln1 Tie2Cre mice and Egln1 Tie2Cre / Fabp45 -/- mice. Human hPAEC from idiopathic PAH patients and healthy donors were used to measure fatty acid-binding protein 4 and 5 (FABP4 and FABP5) expression. siRNA-mediated knockdown of FABP4 and FABP5 and lentivirus-mediated FABP4 and 5 overexpression were performed to study cell proliferation, apoptosis, and glycolysis. Results: scRNA-seq analysis demonstrated that both FABP4 and 5 were highly induced in the ECs of Egln1 Tie2Cre mice. PAECs from IPAH patients also showed higher expression of FABP4 and 5. Knockdown of FABP4-5 reduced EC proliferation, starvation-induced Caspase 3/7 activity, and glycolysis. Overexpression of FABP4-5 promoted EC glycolysis and proliferation. Genetic deletion of Fabp4 and 5 in Egln1 Tie2Cre mice exhibited a reduction of RVSP, RV hypertrophy, and reduction of EC glycolysis gene programming compared to Egln1 Tie2Cre mice. Conclusions: FABP4 and 5 control EC glycolysis and contribute to the development of PAH.
Abstract P3091: Transgenic Expression Of Nrf2 Induces A Pro-reductive Stress And Adaptive Cardiac Remodeling In Mice
Authors: Arun Jyothidasan, Saravanakumar Murugesan, Justin Quiles, Anil Kumar Challa, Senthil Kumar Cinghu, Vivek Nanda, Rajasekaran N Namakkal-Soorappan
Journal: Circulation Research (2022)

Background: NFE2L2, nuclear factor, erythroid 2 like 2 (Nrf2), is a transcription factor that protects cells through maintaining a homeostatic redox state during stress. Constitutive expression of Nrf2 (CaNrf2-TG) was previously shown to be pathological to the heart over time. We tested a hypothesis that the cardiac-specific expression of full length Nrf2 (mNrf2-TG) would moderately increase the basal antioxidant defense, triggering a pro-reductive environment leading to adaptive cardiac remodeling. Methods: Cardiac-specific full-length Nrf2 transgenic (mNrf2-TG) and non-transgenic (NTG) mice hearts on the C57/BL6 background at 7-8 months of age were used to analyze the transcriptome and cardiac structure/function. Next generation sequencing (NGS) for RNA profiling (n=3/group) and qPCR-based validation (n=5/group) of the NGS data were accomplished. Myocardial redox levels and imaging (echocardiography) were performed. Results: Transcriptomic analysis revealed that out of 14665 identified mRNAs, 679 were differently expressed (DEG) in TG hearts. Of 679 DEGs, 429 were upregulated and 251 were downregulated significantly (FC&gt;2, P&lt;0.05). Gene Set Enrichment Analysis revealed that the top altered pathways were (a) Nrf2 signaling, (b) glutathione metabolism and (c) ROS scavenging. A comparative analysis of glutathione redox state in the hearts demonstrated significant differences between pro-reductive vs. hyper-reductive conditions (233 ± 36.7 and 380 ± 68.7 vs. 139 ± 8.6 μM/mg protein in mNrf2-TG and CaNrf2-TG vs NTG). Expression of fetal genes and hypertrophic biomarkers, cytoskeletal genes, histone deacetylases (HDACs), and GATA transcription factors were moderately increased in mNrf2-TG compared to CaNrf2-TG hearts. Non-invasive echocardiography analysis revealed an increase in systolic function (Ejection Fraction) in mNrf2-TG, suggesting an adaption, as opposed to pathological remodeling in CaNrf2-TG mice experiencing a hyper-reductive stress, leading to reduced survival (40% at 60 weeks). Conclusion: The effects of excess Nrf2-driven antioxidant transcriptome revealed a pro-reductive condition in the myocardium leading to an adaptive cardiac remodeling. While pre-conditioning the myocardial redox with excess antioxidants (i.e. pro-reductive state) could be beneficial against oxidative stress, a chronic pro-reductive environment in the myocardium might transition the adaptation to pathological remodeling.